Basis and Linear Combinations

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Question: Express basis vectors $e_1 = (1, 0)$ and $e_2 = (0, 1)$ as linear combinations of $a_1= (2, - 1)$ and $a_2 = (1, 3)$.

I want to know how to solve this.

My answer is following but I am not sure about it...

$e_1= x \cdot a_1 + y \cdot a_2$ and solve for x and y

$e_2= x \cdot a_1 + y \cdot a_2$ and solve for x and y

My goal is to find the basis vectors and write the other vectors as a linear combination of the basis vectors.

Attached is the original matrix and the reduced matrix

I want to know how to do this.

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Your approach works. Here's $e_1$; I'll leave $e_2$ for you.

$e_1=xa_1+ya_2$

$(1,0)=x(2,-1)+y(1,3)$

$1=2x+y$ and $0=3y-x$

$x=3y$ and $7y=1$

$y=\frac17$ and $x=\frac37$.

Check that $(1,0)=\frac37(2,-1)+\frac17(1,3)$.